Document 6543487

FENOCT
%5501
North State Route 2
FirstEnergyNuclear Operating Company
Oak Harbor.Ohio 43449
Raymond A. Lieb
Vice President,Nuclear
419-321-7676
Fax: 419-321-7582
June 27, 2014
L-1 4-185
10 CFR 50.73
ATTN: Document Control Desk
United States Nuclear Regulatory Commission
Washington, D.C. 20555-0001
SUBJECT:
Davis-Besse Nuclear Power Station
Docket Number 50-346, License Number NPF-3
Licensee Event Report 2014-001
Enclosed is Licensee Event Report (LER) 2014-001, "Manual Initiation of the Reactor
Protection System due to Unexpected Indication of Control Rod Movement." This LER
is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A).
There are no regulatory commitments contained in this letter or its enclosure. The
actions described represent intended or planned actions and are described for
information only. If there are any questions or if additional information is required,
please contact Mr. Patrick J. McCloskey, Manager, Site Regulatory Compliance, at
(419) 321-7274.
Sincerly,
R~ayyn A
ie~b
GMW
Enclosure: LER 2014-001
cc:
NRC Region III Administrator
NRC Resident Inspector
NRR Project Manager
Utility Radiological Safety Board
k,
I .
NRC FORM 366
U.S. NUCLEAR REGULATORY COMMISSION
(02-2014)
APPROVED BY OMB NO. 3150-0104
EXPIRES 01/31/2017
Estimated burden per response to comply with this mandatory collection request: 80 hrs.
Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA Privacy and Information Collecbons
,r LICENSEE EVENT REPORT (LER)
• •
Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by
intemet e-mail to [email protected], and to the Desk Officer, Office of Information
and Regulatory Affairs. NEOB-10202 (3150-0104), Office of Management and Budget,
Washington, DC 20503. If a means used to impose an information collection does not display a
currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not
required to respond to, the information collection.
(See Page 2 for required number of
digits/characters for each block)
1. FACILITY NAME
2. DOCKET NUMBER
Davis-Besse Nuclear Power Station
05000
3. PAGE
346
1
OF
3
4. TITLE
Manual Initiation of the Reactor Protection System due to Unexpected Indication of Control Rod Movement
5. EVENT DATE
MONTH
DAY
05
04
YEAR
2014
6. LER NUMBER
YEAR
2014 -
9. OPERATING MODE
7. REPORT DATE
7 7SEQUENTIAL
NUMBER
NO
MONTH
DAY
REV
001
-
27 12
DOCKET NUMBER
FACILITY NAME
DOCKET NUMBER
05000
0 14
D
3El
20.2201(d)
El
20.2203(a)(1)
El 20.2203(a)(3)(i)
L] 20.2203(a)(3)(ii)
El 20.2203(a)(4)
El
20.2203(a)(2)(i)
[] 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
El
50.73(a)(2)(ix)(A)
[]
20.2203(a)(2)(ii)
El
Z 50.73(a)(2)(iv)(A)
El
50.73(a)(2)(x)
El
20.2203(a)(2)(iii)
[] 50.36(c)(2)
El
50.73(a)(2)(v)(A)
El
73.71(a)(4)
0l20.2203(a)(2)(iv)
El
[] 50.73(a)(2)(v)(B)
73.71(a)(5)
El 20.2203(a)(2)(v)
[: 50.73(a)(2)(i)(A)
El
El
El 20.2203(a)(2)(vi)
50.36(c)(1)(ii)(A)
50.46(a)(3)(ii)
El
50.73(a)(2)(i)(C)
El
50.73(a)(2)(ii)(A)
El
50.73(a)(2)(ii)(B)
E]
El 50.73(a)(2)(vii)
El 50.73(a)(2)(viii)(A)
El 50.73(a)(2)(viii)(B)
50.73(a)(2)(v)(C)
NRC Form 366A
TELEPHONE NUMBER (include Area Code)
Gerald M. Wolf, Supervisor, Nuclear Compliance
SYSTEM
1(419) 321-8001
13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT
ALMAU
REOTABLE
7ACAUSE
S7MANU-SYSTEM
COMPONENT
REOTBE
MN,
COMPONENT
FACTURER
TO EPIX
YES (If yes, complete EXPECTED SUBMISSION DATE).
RPTBE
REPORTABLE
TO EPIX
FACTURER
14. SUPPLEMENTAL REPORT EXPECTED
El
OTHER
Specify in Abstract below or in
[] 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
12. LICENSEE CONTACT FOR THIS LER
LICENSEE CONTACT
CAUSE
NM05000
11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
fl 20.2201(b)
10. POWER LEVEL
06
00
YEAR
8. OTHER FACILITIES INVOLVED
FACILITY NAME
Z
NO
15. EXPECTED
SUBMISSION
DATE
MONTH
DAY
ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On May 4, 2014, with the Davis-Besse Nuclear Power Station in Mode 3 and the Reactor Coolant System
at normal operating temperature and pressure, testing was in progress on the Control Rod Drive (CRD)
System. When a Group 8 Axial Power Shaping Rod was withdrawn, indication was received of movement
of a Group 4 Control Rod. The Group 4 Control Rod indication was manually driven to zero percent
indication and the reactor trip breakers were opened from the Control Room.
The erroneous indication was due to improper connection of a Containment Electrical Penetration for CRD
System position indication during the refueling outage. The penetration was rewired to permit startup
activities to continue. The Post-Maintenance Test Manual will be updated to add guidance for testing
Containment Electrical Penetrations associated with the CRD System.
This event is being reported pursuant to 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in manual
actuation of the Reactor Protection System with the reactor not critical.
NRC Form 366 (02-2014)
YEAR
J
NRC FORM 366A
U.S. NUCLEAR REGULATORY COMMISSION
(02-2014)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
1. FACILITY NAME
2. DOCKET
6.LER NUMBER
Y
Davis-Besse Unit Number 1
05000 346
3. PAGE
I REVISION
SEQUENTIAL
Y2
2014
001
-
OF 3
00
NARRATIVE
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].
System Description:
The Davis-Besse Nuclear Power Station (DBNPS) Reactor Protection System (RPS) [JC] initiates a
reactor trip to protect against violating the core fuel design limits and the Reactor Coolant System
(RCS) [AB] pressure boundary during anticipated operational occurrences. The protection and
monitoring systems have been designed to assure safe operation of the reactor. This is achieved by
specifying limiting safety system settings in terms of parameters directly monitored by the RPS, as well
as the Technical Specification (TS) Limiting Conditions for Operation on other reactor system
parameters and equipment performance.
The RPS Manual Reactor Trip provides the operator with the capability to trip the reactor from the
control room in the absence of any other trip condition. Manual trip is provided by two trip push buttons
located in the control room and mounted on either side of the rod control panel. Each push button
operates eight electrically independent switch contacts, one for each side of the undervoltage coil for
each breaker. This trip is independent of the automatic trip system. Power for the Control Rod Drive
Mechanism (CRDM) breaker undervoltage coils and contactor coils comes from the reactor trip
modules (RTMs). Opening of the switch contacts opens the lines to the breakers, tripping them. The
switch contacts also energize the breaker shunt trip mechanisms. There are two separate push button
switches in series, with the output of each of the four RTMs. Pressing either push button will remove
power from all four CRDM trip breakers, initiating a reactor trip.
The Control Rod Drive System [AA] consists of 61 CRDMs and the associated equipment needed to
provide safe and reliable control of the Control Rod Assemblies used to control the reactivity level in the
reactor fuel. The CRDMs are mounted on flanged nozzles on the top of the reactor vessel closure
head. Control of the CRDMs is accomplished by operating the CRDMs in eight groups. There are four
to twelve CRDMs in each group and all of the CRDMs in a group operate in unison. Groups 1 through 4
are operated in a safety rod mode, Groups 5 through 7 are operated in a regulating rod mode, and
Group 8 is assigned to the Axial Power Shaping Rods (APSRs). The CRDMs in Groups 1 through 7 are
designed so that they will release the Control Rod Assemblies upon loss of power to the CRDM stator.
The CRDMs in Group 8 are equipped with an anti-trip device so that they will not release the
leadscrews and Control Rod Assemblies upon loss of electrical power to the stators. CRDMs in each of
these groups are located in a dispersed pattern; however, there is location symmetry in each quadrant
of the reactor. All the CRDMs of a group move the Control Rod Assemblies in unison to provide an
even rate of controlling reactivity in the reactor fuel.
DESCRIPTION OF EVENT:
On May 4, 2014, the DBNPS was in Mode 3 with the Reactor Coolant System at normal operating
temperature and pressure performing startup activities from the Eighteenth Refueling Outage. Activities
were in progress to obtain Zero Percent and In Limit Lights for the Group 8 APSRs. While performing
this activity, unexpected outward movement was indicated on Control Rod 4-9, which showed the rod
moved from approximately zero percent to 2.33 percent when Group 8 was withdrawn to clear the In
Limit Light. Also, when Control Rod 8-8 was withdrawn on the Auxiliary Power Supply, Control Rod 4-9
indicated movement from 2.33 percent to 5.96 percent while no movement was observed for Control
Rod 8-8. Control Rod 4-9 indication was manually driven back to zero percent indication from the
control panel and the reactor trip breakers were opened from the Control Room.
NRC FORM 366A (02-2014)
U.S. NUCLEAR REGULATORY COMMISSION
NRC FORM 366A
(02-2014)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
1. FACILITY NAME
2. DOCKET
YEAR
Davis-Besse Unit Number 1
0.5000 346
I
6. LER NUMBER
IINUMBER
REVISION
SEQUENTIAL
NUMBER
Y3
2014
3. PAGE
OF 3
001
-
00
NARRATIVE
CAUSE OF EVENT:
During the Eighteenth Refueling Outage, a Containment Electrical Penetration [NH-PEN] was replaced
that contained wiring for the affected CRDM position indications. When the old penetration was being
disconnected, it was discovered the cable designation scheme tags on the wires inside of containment
were difficult to read. When the new penetration was installed, new cable scheme tags were placed on
the nine existing field cables containing five wires each. The penetration was apparently connected
improperly due to some of the cable scheme tags not being replaced correctly during the penetration
replacement. The post maintenance testing detailed in the work order for replacement of the
Containment Electrical Penetration was not sufficient to detect the improper connections prior to startup
testing of the Control Rod Drive System.
ANALYSIS OF EVENT:
Upon indication of the unexpected outward Control Rod movement, the rod that indicated outward
movement was manually inserted to zero percent indication from the control panel. The manual reactor
trip pushbuttons in the Control Room were depressed to open the reactor trip breakers. All safety
equipment performed as designed, and no negative reactivity was added when the reactor trip breakers
were opened because all Control Rods were already fully inserted into the reactor core. Therefore this
event was of very low safety significance.
Reportability Discussion:
Following a separate event that occurred on May 5, 2014, in which the manual reactor trip pushbuttons
in the Control Room were also depressed to open the reactor trip breakers (refer to DBNPS LER 2014002), this May 4, 2014 event was reviewed for reportability. On May 8, 2014, this intentional manual
actuation of the RPS with the reactor not critical was determined to be reportable per 10 CFR
50.72(b)(3)(iv)(A). The NRC was verbally notified of this event per 10 CFR 50.72(b)(3)(iv)(A) at 1746
hours on May 9, 2014, via Event Number 50097. The late notification per 10 CFR 50.72 has been
entered into the DBNPS Corrective Action Program. This issue is being reported in accordance with 10
CFR 50.73(a)(2)(iv)(A) as an event that resulted in manual actuation of the RPS with the reactor not
critical. No safety functions were lost as a result of this issue, and all TS required actions were met.
CORRECTIVE ACTIONS:
Because of the plant conditions at the time of discovery, an Engineering Change Package was
implemented to rewire the Electrical Penetration from the outside of Containment to create a
functionally equivalent circuit for the CRDM position indications.
The Post-Maintenance Test Manual will be updated to add guidance for testing CRDM associated
penetrations to include functional testing.
PREVIOUS SIMILAR EVENTS:
There have been no Licensee Event Reports submitted for the DBNPS in the past three years where
the RPS was manually initiated due to Control Rod Drive System issues.
NRC FORM 366A (02-2014)